1. Field Of The Invention
This invention relates generally to umbilical cord clamps, specifically to a device that simultaneously severs and clamps an umbilical cord of a newborn infant.
2. Prior Art
A fetus receives its blood supply and nutrients from its mother through an umbilical cord connected between the baby's abdomen and the mother's placenta. Immediately after the birth of the baby, the umbilical cord is severed to separate the baby from its mother. Blood loss from the mother and baby is typically minimized by clamping the umbilical cord with two slightly spaced clamps before the cord is cut between the clamps. This procedure requires three separate devices--two clamps and a scalpel--and is somewhat time consuming.
Many umbilical cord clamping devices with built-in cutting blades for both cutting and clamping umbilical cords have been proposed. U.S. Pat. No. 4,938,215 to Schulman et al. (1990) shows an umbilical cord clamping device that includes two clamps held together side-by-side by a single shear pin. A lever with a cutting blade is positioned between abutting arms of the clamps and pivotally attached to the hinge of the clamps. The movement of the lever between the arms is impeded by the shear pin. The clamps are closed upon an umbilical cord by pressing the lever downwardly. After the clamps are fully closed, the shear pin is broken by further pressure upon the lever, so that the blade is brought down upon the umbilical cord to sever it. However, breaking the shear pin requires a moderate amount of force, so that the device is somewhat difficult to operate. Furthermore, some blood is splashed outwardly from the device during the instant when the umbilical cord is cut, so that surrounding persons are exposed to the danger of contacting potentially infectious blood.
U.S. Pat. No. 4,856,517 to Collins et al. (1989) shows an umbilical cord clamping device that includes two spaced apart small clamps fitted within a larger clamp for simultaneous closing. After the clamps are closed around an umbilical cord, they are locked in a closed position by a latch. A knob with a blade attached thereto is fitted within a slot in the large clamp between the smaller clamps. The knob is manually moved forwardly to sever the cord with the blade. When the knob has reached the end of the slot, the latch is engaged and released by the knob to allow the opening and removal of the larger clamp, but the small clamps remain clamped around the umbilical cord. This device requires two separate steps to operate, i.e., clamping the cord, and then moving the blade. Furthermore, blood is splashed outwardly from the slot during the cutting operation. This device includes five pans--one large clamp, two small clamps, a knob, and a blade--so that manufacturing cost is relatively high.
U.S. Pat. No. 4,781,188 to Collins (1988) shows an umbilical cord clamping device that includes two spaced apart small clamps fitted within a larger clamp for simultaneous closing. A fixed blade attached to one arm of the larger clamp automatically cuts an umbilical cord when the device is clamped thereon. When the device is released, the larger clamp is opened automatically and separated from the smaller clamps, which are latched closed on the severed ends of the umbilical cord. However, blood will splash outwardly through the front of the larger clamp when the umbilical cord is severed.
U.S. Pat. No. 4,716,886 to Schulman et al. (1988) shows an umbilical cord clamping device that includes two clamps held together side-by-side by a single shear pin. A blade is slidably positioned between abutting arms of the clamps. The movement of the blade between the arm is impeded by the shear pin. The clamps are closed upon an umbilical cord by pressing the blade downwardly. After the clamps are fully closed, the shear pin is broken by further pressure upon the blade, so that the blade is moved inwardly to sever the umbilical cord. However, this device is somewhat difficult to operate, due to the need to break the shear pin. Furthermore, it cannot prevent blood from splashing onto surrounding persons.
U.S. Pat. No. 4,026,294 to Mattler (1977) shows an umbilical cord clamping device that includes two clamps attached to the cutting blades of a scissors-like installation device by breakable bridges. Squeezing the handles of the installation device closes the clamps around the umbilical cord. Squeezing the handles further breaks the bridges to separate the cutting blades from the clamps, and close the blades to sever the umbilical cord. However, this device is relatively complicated to setup and use, and requires many parts, including the relatively expensive installation device.
U.S. Pat. No. 3,631,858 to Ersek (1972) shows an umbilical cord clamping device that includes two clamps held together side-by-side by a long breakable bridge. A cutting blade is fixedly attached to one of the arms. When the clamps are closed upon an umbilical cord, the blade first severs the cord, then breaks the bridge to separate the clamps. However, the device is somewhat difficult to operate, due to the high force necessary to cut the long bridge. It also cannot prevent blood from splashing onto surrounding persons.
U.S. Pat. No. 3,323,208 to Hurley, Jr. (1967) shows an umbilical cord clamping device that includes two clamps held together side-by-side by pins on one clamp frictionally fitted into sockets on an abutting edge of the other clamp. A blade positioned between the clamps cuts the cord when the clamps are closed. However, the short pins cannot reliably hold the clamps together, so that accidental separation can occur. It also cannot prevent blood from splashing onto surrounding persons.
An umbilical cord clamp sold under the trademark "Cordguard"by Utah Medical includes a sliding blade arranged on one of two hingeably connected, lockable arms. After the arms are locked closed around an umbilical cord, the blade is pressed inwardly to sever it. This device is somewhat inconvenient to use, because it requires separate clamping and cutting steps.